function ParallelPort_ReadDataValues(
  BaseAddr: word;
  var I_D0, I_D1, I_D2, I_D3, I_D4, I_D5, I_D6, I_D7: boolean): boolean;

var
  Data: DWord;
  Addr: DWord;

begin
  // work at Data register address
  Addr := BaseAddr + 0;

  // init data (only used if error occurs during read)
  I_D0 := false;
  I_D1 := false;
  I_D2 := false;
  I_D3 := false;
  I_D4 := false;
  I_D5 := false;
  I_D6 := false;
  I_D7 := false;

  // read data value on LPT port if system IS NOT WinNT
  if Win32Platform <> VER_PLATFORM_WIN32_NT then
  begin
    try
      Case DataType of
        DataType_Byte :
          asm
            mov edx,Addr
            xor eax,eax
            in al,dx
            mov Data,eax
          end;
        DataType_Word :
          asm
            mov edx,Addr
            xor eax,eax
            in ax,dx
            mov Data,eax
          end;
        DataType_DWord:
          asm
            mov edx,Addr
            xor eax,eax
            in eax,dx
            mov Data,eax
          end;
        end;
      except
        result := false;
        exit;
      end;
    end
    else

  // read data value on LPT port if system IS WinNT
  begin
    try
      if ZLIOStarted then
        Data := ZLIOPortRead(Addr, DataType_Byte)
      else
      begin
        Data := 0;
        result := false;
      end;
    except
      result := false;
      exit;
    end;
  end;

  // extract bits value for individual data line
  I_D7 := (((Data and 128) div 128) = 1);
  I_D6 := (((Data and 64) div 64) = 1);
  I_D5 := (((Data and 32) div 32) = 1);
  I_D4 := (((Data and 16) div 16) = 1);
  I_D3 := (((Data and 8) div 8) = 1);
  I_D2 := (((Data and 4) div 4) = 1);
  I_D1 := (((Data and 2) div 2) = 1);
  I_D0 := (((Data and 1) div 1) = 1);
  result := true;
end;